Electronic photocopying apparatus

ABSTRACT

An electronic photocopying apparatus in which a photosensitive member comprising a photosensitive layer of photoconductive material supported on a transparent supporting member and a supporting frame holding the photosensitive layer together with the transparent member is placed on a rotary table rotated for subjecting the photosensitive member to a series of processes for the image pick-up and reproduction, thereby providing a monochromatic or polychromatic image reproduction without staining the supporting frame of the photosensitive member.

Unite States atent [1 1 Yamaji et a1. Mar. 5, 1974 1 ELECTRONIC PHOTOCOPYING 3,292,486 12/1966 Mey 355/4 APPARATUS 3,679,301 7/1972 lnoue 4 355/4 3,532,422 10/1970 McFar1ane.. 355/4 [75] Inventors: Keizo Yamaji; Akira K h 3,324,764 6/1967 Altman 355/4 both of Tokyo, Japan 3,181,418 5/1965 Durlofsky 355/4 [73] Assignee: Canon Kabushiki Kaisha, Tokyo,

Japan Primary Examiner-Samuel S. Matthews [22] Filed: May 5 1972 Assistant Examiner-Michael L. Gellner Attorney, Agent, or FirmFitzpatrick, Cella, Harper [21] Appl. No.: 250,805 & ScintO Related U.S. Application Data Continuation of Ser. No. 37,725, May 15, 1970, abandoned.

Foreign Application Priority Data May 22, 1969 Japan 44-40044 May 23, 1969 .lapan.... 44-48233 May 31, 1969 Japan 44-51118 U.S. Cl. 355/4 Int. Cl G03g 15/22 Field of Search 355/4 References Cited UNITED STATES PATENTS 9/1970 Tanaka et all 355/4 [57] ABSTRACT An electronic photocopying apparatus in which a photosensitive member comprisinga photosensitive layer of photoconductive material supported on a transparent supporting member and a supporting frame holding the photosensitive layer together with the transparent member is placed on a rotary table rotated for subjecting the photosensitive member to a series of processes for the image pick-up and reproduction, thereby providing a monochromatic or polychromatic image reproduction without staining the supporting frame of the photosensitive member.

3 Claims, 6 Drawing Figures PATENTEUIAR 5 m4 v 3395; 91 7' sum 1 OF 2 ELECTRONIC PHOTOCOPYING APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a novel electronic photocopying apparatus, and more particularly to such an apparatus for providing a polychromatic image reproduction on a photosensitive member having a photosensitive layer of photoconductive material held by a supportingframe.

2. Summary of the Invention According to the present invention, a photosensitive member comprising a photosensitive layer of photoconductive material supported on a transparent supporting member and a supporting frame holding the photosensitive layer together with the transparent member for use as a slide or microfilm card is placed on a rotary member, which is rotated for subjecting the photosensitive member to a series of processes such as electric charging, exposure, development, fixing and drying to thereby provide a monochromatic image reproduction or a polychromatic image reproduction resulting from repetition of the process required for the monochromatic image reproduction.

It is an object of the present invention to provide an electronic photocopying apparatus which ensures the positioning ofa photosensitive member on a surface for supporting thereon the photosensitive member and thereby provide an image reproduction free of color mismatching.

It is another object of the present invention to provide an electronic photocopying apparatus in which the replacement of color resolving filters and developing rollers is effected under automatic control.

It is still another object of the present invention to prevent developer from sticking to the supporting frame of the photosensitive member to stain the same.

Other objects and features of the present invention will be understood from the following description taken in conjunction with the accompanying drawings as well as from the appended claims.'

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an example of the photosensitive member according to the present invention;

FIG. 2 is an enlarged side view showing the photosensitve layer and transparent member forming the photosensitive member of FIG. 1;

' FIG. 3 is a cross-sectional view of the photosensitive layer and transparent supporting member of FIG. 2;

FIG. 4 is an elevational view of the electronic photocopying apparatus according to' an embodiment of the present invention;

FIG. 5 is aplan view of a portion of the FIG. 4 apparatus; and

FIG. 6 is a partly cut-away front view of the rotary developing device according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be described in detail by way of example with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, a photosensitive member held by a supporting frame for use as a slide or microfilm card is first prepared by supporting a photosensitive layer 1 formed of an organic photoconductive material on a transparent supporting member 2 formed of a material such as polyethylene terephthalate, and subsequently assembling the photosensitive layer 1 and transparent supporting member 2 to a supporting frame 3 formed of rigid thick paper so as to form a complete photosensitive member 4. Since the phtosensitive layer 1 is formed of an organic photoconductive material as described above, it is transparent and the resultant photosensitive member 4 is also transparent. Such a transparent photosensitive member is suitable for use as a slide or microfilm card which is used with transmitted light after an image is formed thereon.

By using the above-described photosensitive member, the present invention provides a copying apparatus which results in no color mismatching. The photosensitive member is rotated in a plane. Above and along the circular path of the photosensitive member there are provided various means as designated by 6 to 10 for electrically charging the photosensitive member, ex-

posing it to light, developing, fixing and drying the same. One full rotation of the photosensitive member 4 completes a monochromatic image reproduction, and repetition of such rotation provides a polychromatic image reproduction.

A rotary disc 5 for supporting thereon the photosen sitive member 4 is electrically conductive and grounded. The photosensitive member 4 is held on the upper surface of the rotary disc 5 by a holder 11 provided thereon. Developing means 8, as shwon in FIG. 6, comprises, for example, three separate developing rolls 12 12 and 12 representing three colors and rotatably mounted on a common rotatable supporting member 13 so that these rolls contact the photosensitive member 4 while being driven to rotate at the same velocity as the photosensitive member 4 or at a predetermined velocity relative to the photosensitive member 4. Each of the developing rolls 12 and 12 comprises a conical cylinder 15 formed with fine apertures 14, and a porous coating 16 such as sponge or the like applied to the entire side wall of the conical cylinder 15. Each of the cylinders 15 contains therein a different developer 17 consisting of a different coloring matter. The developer 17 in the cylinders 15 percolats through the coating 16 due to capillary action in accordance with a desired rate of consumption when the rolls 12 to 12 rotate in contact with the photosensitive member 4. If the developer 17 in each cylinder 15 is used up, the developing means 8 is raised by being rocked in the direction as indicated by an arrow in FIG. 6, and a fresh supply of developer is provided to each developing roll by removing a sealing plug 18 which normally closes the forward end of the developing roll.

With the photosensitive member 4 held on the rotary disc 5 by the holder 11, a start buttoon (not shown) is depressed to actuate positioning means 19 so as to disengage a plunger 20, against the force of a spring 21,

sensitive member 4 reaches a position for exposure shown by imaginary lines, the plunger urged away from the circumference of the rotary disc 5 by the spring 21 is again engaged by the positioning means 19 and at the same time the motor 23 stops driving the rotary disc 5, whereby the photosensitive member is set in place for the exposure effected by exposure means 7.

When the photosensitive member 4 is thus set in its exposure position, the image or picture on a document D to be copied resting on a document supporting table 25 is illuminated by sources of light 26 and projected upon the photosensitive member 4 through a color resolving filter 27 and a projection lens 28, whereby the photosensitive member 4 is exposed to a first color light to form an electrostatic latent image corresponding to that color.

Upon completion of the exposure, the plunger 20 is again disengaged from the mating notch 24 so as to allow the rotary disc 5 to be again rotated in the direction of the arrow by the drive motor 23. The photosensitive member'4 is thus moved toward the developing means 8 and as it passes this means, the photosensitive member 4 is contacted by the roll 12 so that the electrostatic latent image formed thereon is developed and visualized by a first color developer provided from the roll 12 The photosensitive member 4 is further carried to the fixing means 9 and drying means 10, where it is fixed and dried respectively, and when the rotary disc 5 completes its one rotation to return to the initial position as shown in FIG. 5, the plunger 20 engages the notch to lock the rotary disc 5 and thus the image formation in .the first color is completed. The positioning means 19 may take any other suitable form than that shown in FIG. 5.- g I When the rotary disc 5 stops in the position of FIG. 5, a signal produced by signal generating means 30 provided in the rotary disc 5 is detected by detection means 31 provided on the body of the copying machine, and the detected signal drives a drive motor 29 which replaces the first color resolving filter 27 by a second color resolving filter. Thereupon, the start button (not shown) is again depressed to rotate the rotary disc 5 so that the photosensitive member 4 is moved through the electrically charging means 6 to the exposure means 7 in the same way as already described, When the photosensitive member 4 reaches the exposure means 7, the positioning means 19 is actuated to stop the rotary disc 5. Thereby the photosensitive member 4 can be set in exactly the same exposure position as in the preceding cycle, and thus no mismatching takes place between the first and second expsoures or between the first and second colored images formed on the photosensitive member.

The second exposure is effected through the second color resolving filter 27, which exposes the photosensitive member 4 to a color different from the color used for the first exposure, and thereby an electrostatic latent image corresponding to the second color is formed on the photosensitive member, in superposed relationship with the first electrostatic latent image, Thereafter the photosensitive member 4 is carried to the developing means 6 so that the second latent image thereon is developed and visualized by the second developing roll 12 which is already brough into its operative position by a motor 32 in association with the replacement of the color resolving filter 27. Subsequently the photosensitive member 4 is carried through the fixing means 9 and drying means 10 to return to the position of FIG. 5, where it is stopped and completes the second color image formation.

The above described cycle of operation may be repeated in accordance with the number of colors desired for the image reproduction. For example, a single cycle of operation is only required for a monochromatic reproduction, and three or four cycles are required for the natural color printing.

The shown fixing means 9 comprises a conical roll 33 of sponge-like material impregnated with a fixing solution, and this fixing means rolls on the image-bearing surface of the photosensitive member 4 to fix the developed image. The fixing process may alternatively be accomplished directly by heat or solution depending on the selection of the material for the transparent supporting member 2 of the photosensitive member 4 or the selection of the developing toner.

The supporting frame 3 holding the photosensitive material is treated for oil resistivity soas to be protected against the corrosion resulting from the carrier (petroleum solution) contained in the developer. However, the material used for such treatment is usually a substance of high resistance which would cause the supporting frame 3 also to be electrically charged. Any electric charge present in the supporting frame 3 may attract the toner in the developer and such attracted toner will stick to the supporting frame 3 and stain the same. Therefore, the supporting frame 3 is formed of an electrically conductive material or treated for oilresistive conductivity so as to prevent the supporting frame 3 from being electrically charged. Nevertheless, such electrically conductive supporting frame may act as a shield during the electrically charging process and thereby the portions of the photosensitive layer adjacent to the supporting frame may be insufficien-tly charged or may not be charged at all. If the abovedescribed treatment should fail to completely remove all the possible electric charges from the supporting frame 3, a method may be resorted to whereby a grounded conductive member is contacted with the supporting frame 3 after the electrically charging process but before the exposure process, so as to remove any electric charge present in the supporting frame, namely, in the non-image-bearing area of the photosensitive member 4. This method, however, permits the electric charges to remain in the minute recesses pecu- For this purpose, as shown in FIG. 4, a sheet of glass 25 is attached to the table 25 for supporting the document D so as to control the effective exposed portion of the document, and a reflection surface 25 formed of a white paint, metal sheet or other suitable material is provided peripherally of the document supporting table 25, so that when the document D is illuminated by the sources of light 26 to project the image to be copied upon the photosensitive layer of the photosensitive member 4 through the color resolving filter 27 and projection lens 28, the supporting frame 3 of the photosensitive member 4 is also illuminated easily by light L without the necessity of providing any specific illuminating means or process. Althernatively, the same result may be achieved by forming openings in the reflection shades 26 of the light sources 26 so as to direct the light therethrough to the supporting frame 3. It is also possible that the photosensitive member 4 uses no supporting frame 3 but comprises the photosensitive material alone, and in this case the removal of the unnecessary electric charges is effected by illuminating the non-image-bearing portion of the photosensitive member 4.

With the arrangement of the present inventionas described above, the photosensitive member is moved round only in one direction and the control thereof is very simple and easy while the problem of color mismatching for polychromatic reproduction can be completely solved. Further, the replacement of the color resolving filters and developing rolls is controlled by the signal generator provided in the rotary disc for holding the photosensitive member and the detection means provided to detect the signal, and this leads to a highly accurate and reliable performance of the copying machine which is free of failure in copying opera-.

tion. Furthermore, the sticking of the developer to the supporting frame of the photosensitive member is effectively prevented by illuminating the supporting frame with part of the light from the sources of light and by previously coating or impregnating the supporting frame with a photoconductive material.

Examples of the photosensitive member used with the present invention are shown below.

1 The transparent organic photoconductive material forming the photosensitive layer 1 may be: condensed-ring aromatic compound such as anthracene carbozole, anthraquinone, perylene or the like; heterocyclic compound such as acyl hydrazone derivative, triphenyl pyrazoline derivative or the like; or poly- N-vinyl carbazole or the like.

2. The transparent supporting member 2 may be formed of Mylar (trade name), glass or acrylic acid resin. If use is made of glass or acrylic acid resin which has rigidity, the supporting frame 3 may be omitted. The transparent supporting member, if subjected to a suitable treatment for electrical conductivity, will reduce the fogging of the image formed.

3. The supporting frame may comprise thick paper.

acrylic acid, polyacrylamide, polyethylene imine, polyvinyl alcohol, polyvinyl pyrrolidine or the like; watersoluble cellulose derivative such as carboxymethylcellulose, methyl or ethyl cellulose; animal or vegetable protein such as gelatin or casein; viscous vegetable substance such as gum arabic, sodium alginate; inorganic salt such as sodium chloride, ammonium chloride, potassium chloride, calcium chloride, sodium nitrate or the like; various surface activators; quaternary ammonium salt polymer such as poly-(N, N-dimethyl-3, 5- methylene) piperidinium chloride, polyvinyl benzyl trimethylene ammonium chloride.

What is claimed is:

1. An electronic photocopying apparatus capable of polychromatic image reproduction, comprising:

a. a photosensitive member including a transparent supporting member, a photosensitive layer of photoconductive material disposed on said transparent supporting member, and a supporting frame for supporting said photosensitive layer of said transparent supporting member,

b. rotatably movable carrying means for detachably holding said supporting frame,

c. a series of electrophotographic process means including means for charging said photosensitive member, a plurality of different colored light filters, means for exposing an original image on the surface of said photosensitive member to form an electrostatic latent image thereon through a said filter of desired color, and means for developing said electrostatic latent image including a plurality of developing rollers having different colors corresponding to said filter colors, said series of process means being disposed sequentially adjacent to the upper surface of said carrying means,

d. means for rotating and means for stopping said carrying means to subject said photosensitive member to said series of electrophotographic process means in one complete revolution of said carrying means,

e. means for sequentially exchanging said filters on completion of each revolution of said carrying means, and v f. means for sequentially exchanging said developing rollers on completion of each revolution of said carrying means, wherein said carrying means in cludes a rotatable disc, and wherein said means for stopping said carrying means includes a first notched portion on the periphery of said disc corresponding to the initial position of rotation of said carrying means and a second notched portion on the periphery of said disc corresponding to the position of exposing said original image on said photosensitive member, and a retractable plunger element engageable with said notched portions to stop said carrying means.

2. An electronic photocopying apparatus capable of polychromatic image reproduction, comprising:

a. a photosensitive member including a photosensitive layer of photoconductive material spread on a transparent supporting member and a supporting frame for supporting said photosensitive layer and said transparent supporting member,

b. a rotary member carrying means for detachably holding said supporting frame,

c. a series of electrophotographic process means including means for charging said photosensitive member, means for exposing an original image on the surface of said photosensitive member to form d'. means for rotating and means for stopping said rotary member to subject said photosensitive member to said series of electrophotographic process means in one complete revolution of said rotary member,

e. signal generating means and detection means for detecting the signal generated by said signal generating means to indicate completion of one revolution of said rotaty member,

f. means for sequentially exchanging said filters in response to said signal, and

g. means for sequentially exchanging said developing rollers one after another in response to said signal.

3. An electronic photocopying apparatus according to claim 2, wherein reflection members are provided on the back side of said table for directing part of the light from said illuminating lamps through a lens to only said supporting frame, when said original image is being exposed to said photosensitive member through said lens.

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1. An electronic photocopying apparatus capable of polychromatic image reproduction, comprising: a. a photosensitive member including a transparent supporting member, a photosensitive layer of photoconductive material disposed on said transparent supporting member, and a supporting frame for supporting said photosensitive layer of said transparent supporting member, b. rotatably movable carrying means for detachably holding said supporting frame, c. a series of electrophotographic process means including means for charging said photosensitive member, a plurality of different colored light filters, means for exposing an original image on the surface of said photosensitive member to form an electrostatic latent image thereon through a said filter of desired color, and means for developing said electrostatic latent image including a plurality of developing rollers having different colors corresponding to said filter colors, said series of process means being disposed sequentially adjacent to the upper surface of said carrying means, d. means for rotating and means for stopping said carrying means to subject said photosensitive member to said series of electrophotographic process means in one complete revolution of said carrying means, e. means for sequentially exchanging said filters on completion of each revolution of said carrying means, and f. means for sequentially exchanging said developing rollers on completion of each revolution of said carrying means, wherein said carrying means includes a rotatable disc, and wherein said means for stopping said carrying means includes a first notched portion on the periphery of said disc corresponding to the initial position of rotation Of said carrying means and a second notched portion on the periphery of said disc corresponding to the position of exposing said original image on said photosensitive member, and a retractable plunger element engageable with said notched portions to stop said carrying means.
 2. An electronic photocopying apparatus capable of polychromatic image reproduction, comprising: a. a photosensitive member including a photosensitive layer of photoconductive material spread on a transparent supporting member and a supporting frame for supporting said photosensitive layer and said transparent supporting member, b. a rotary member carrying means for detachably holding said supporting frame, c. a series of electrophotographic process means including means for charging said photosensitive member, means for exposing an original image on the surface of said photosensitive member to form an electrostatic latent image thereon, said last named means including a table for supporting thereon a document bearing said original image to be copied, illuminating lamps disposed adjacent said table, color separation filters interposed between said table and said photosensitive member; means for developing said electrostatic latent image including developing rollers, fixing means and drying means disposed sequentially adjacent to the upper surface of said rotary member, d. means for rotating and means for stopping said rotary member to subject said photosensitive member to said series of electrophotographic process means in one complete revolution of said rotary member, e. signal generating means and detection means for detecting the signal generated by said signal generating means to indicate completion of one revolution of said rotaty member, f. means for sequentially exchanging said filters in response to said signal, and g. means for sequentially exchanging said developing rollers one after another in response to said signal.
 3. An electronic photocopying apparatus according to claim 2, wherein reflection members are provided on the back side of said table for directing part of the light from said illuminating lamps through a lens to only said supporting frame, when said original image is being exposed to said photosensitive member through said lens. 